The hotel room’s AC unit hummed, a stream of cold air cutting across Katsuki’s bare shoulders as he stood before the floor-length mirror, wrestling with his cufflinks. The starched white shirt felt like a straitjacket. Eijiro, already dressed in his charcoal gray suit, leaned against the doorframe, arms crossed.

“You look like you’re prepping for a deposition, not your wedding,” Eijiro said, his voice low.

“It’s a ceremony. It’s procedural.” Katsuki’s fingers fumbled the silver clasp. He could see the fresh cut across his knuckles in the reflection.

“Bullshit. You’re wound tighter than a spring. Is he here?”

Katsuki didn’t answer. The silence was answer enough.

“I’m not leaving you alone in this hotel,” Eijiro stated, pushing off the frame. “I’ll walk you down the hall myself. Stick to you like glue at the reception. That little—”

A sharp, cheerful knock cut him off. The door swung open before either could speak.

Denki Kaminari leaned in, his fluffy blonde hair catching the hallway light, the single black streak a bold slash. He wore a sleek, dove-gray suit that clung to his slight, curvy frame, the jacket unbuttoned over a sheer black shirt. His bright yellow eyes swept the room, landing on Eijiro. A slow, knowing smile spread across his face.

“Oops! Sorry, guys! Looking for the, uh, best man? Izuku said you might need help with your tie or something.” Denki’s voice was all sunshine and mischief as he sauntered in, closing the door behind him. He looked directly at Eijiro. “You must be Kirishima.”

Eijiro straightened, his professional mask slipping for a second into pure, unguarded shock. His eyes widened, then darted from Denki’s face down his body and back up. A deep, unmistakable flush crept up his neck, staining his cheeks crimson.

“You… I…” Eijiro stammered, uncharacteristically lost. He cleared his throat, forcing his lawyer’s cadence back. “Do I know you?”

Denki laughed, a light, sparkling sound. He stepped closer, within Eijiro’s space. “Doubt it. But you might know my work. ‘Kaminari’s Circuitry.’ ‘Shocking Service.’ Ring any bells?”

Eijiro’s breath hitched. The blush deepened. He was a man who argued before judges, but now he looked utterly disarmed. “You’re… him.”

“The one and only.” Denki’s gaze was bold, appreciative, trailing over Eijiro’s muscular build. “Wow. The camera does not do you justice. You’re way hotter in person, Mr. Best Man.”

Katsuki watched, his cufflinks forgotten. He saw the plan unfolding with perfect, brutal clarity. Izuku’s move. Remove the guard. His chest tightened.

“Denki,” Katsuki said, his voice a graveled warning.

“Relax, Kacchan,” Denki chirped, not looking away from Eijiro. “I’m just here to borrow this handsome piece of wedding infrastructure. Izuku said you two are, like, super stressed. Thought I could whisk him away for a pre-ceremony drink. Calm the nerves.” He finally glanced at Katsuki, his smile sharpening. “You don’t need him right now, do you?”

“Eijiro,” Katsuki tried.

Eijiro was still staring, his mouth slightly agape. He’d seen every video. Knew every scene. The realization was a physical blow, leaving him flustered and pink.

“Go,” Katsuki heard himself say, the word hollow. “It’s fine.”

Eijiro blinked, tearing his eyes from Denki. “Katsuki—”

“I said go.” The finality in Katsuki’s tone brooked no argument. It was the voice he used in court to end a line of questioning. He turned back to the mirror, grasping the dresser’s edge until his knuckles turned white.

He listened to the soft sounds of them leaving: Denki’s playful murmur, Eijiro’s stuttered reply, the door clicking shut.

The cold air from the vent poured over him. The room was silent. He was alone. Exactly as intended.

The door opened again, without a knock.

Izuku stood in the hallway, backlit by the muted hotel sconces. He’d changed into his suit for the ceremony, a slim-fit green tuxedo that hugged his lean frame, the bowtie already dangling loose around his open collar. His green curls were artfully messy. He stepped inside and let the door swing shut behind him, the click echoing in the silent room.

Katsuki didn’t turn from the mirror. He watched the reflection, watched Izuku’s slow approach. “Get out.”

“Denki’s good, isn’t he?” Izuku’s voice was a low, pleased hum. He came to stand just behind Katsuki’s shoulder, close enough for Katsuki to smell his clean, citrus shampoo. “Your big, strong best man folded like a cheap suit. He’s probably in a stairwell right now, getting his dick sucked.”

“You’re disgusting.”

“I’m efficient.” Izuku’s eyes met Katsuki’s in the glass. His gaze dropped to Katsuki’s fumbling hands. “You can’t even do your cufflinks. Let me.”

“Don’t touch me.”

Izuku ignored him. His fingers, deft and cool, brushed Katsuki’s wrist. He took the silver clasp, his touch light and businesslike. He fastened the first cufflink with a quiet snap, his knuckles grazing the pulse point. Katsuki’s breath hitched. He stood rigid, a statue in a starched shirt.

“See?” Izuku murmured, moving to the other sleeve. “You need me. Who else is going to get you ready for your big day, Daddy?”

The name, whispered like that, lanced through Katsuki’s gut. He watched Izuku’s lashes lower, the fan of freckles across his nose. His own reflection was a stranger—jaw tight, eyes dark with a hunger he could no longer pretend was anger.

Izuku finished the second cuff. He didn’t pull away. His hands slid up Katsuki’s forearms, over the crisp cotton, to his biceps. He rested his chin on Katsuki’s shoulder, his cheek against Katsuki’s. Their faces side-by-side in the mirror. “Look at us,” Izuku breathed. “Don’t we look good together?”

“Stop it.” The command had no force.

“You’re shaking.” Izuku’s hands smoothed over Katsuki’s shoulders, down his chest. His palms flattened over Katsuki’s pectorals, feeling the hard muscle beneath the shirt. “All wound up. You’ve been like this all morning. Since the gym. Since the club.” His thumbs brushed over Katsuki’s nipples, a deliberate, circling pressure through the fabric.

Katsuki’s eyes slammed shut. A low sound escaped him, part groan, part surrender.

“There it is,” Izuku whispered, triumphant. He pressed his hips against the back of Katsuki’s tailored trousers. “I’ve been thinking about you all day. About tonight.”

“There is no tonight,” Katsuki gritted out, his eyes still closed. “I’m marrying your mother.”

“You are.” Izuku’s lips brushed the shell of Katsuki’s ear. “And in a few hours, you’ll put a ring on her finger. You’ll kiss her in front of everyone. You’ll promise her forever.” His hand slid down, over Katsuki’s stomach, lower. “And the whole time, you’ll be thinking about this.” His palm cupped Katsuki through his trousers, feeling the thick, heavy outline of his cock, already hard and straining against the zipper. “Won’t you?”

Katsuki didn’t move. His hands stayed clenched on the edge, his reflection a portrait of furious, frozen want. Izuku’s palm was a brand through the wool, a perfect, taunting weight.

“You’re going to stand there,” Izuku whispered, his lips still grazing Katsuki’s ear. “You’re going to let me get you ready. A groom shouldn’t be this tense.”

His fingers worked the button of Katsuki’s trousers, the sound obscenely loud. The zipper hissed down. Cool air hit Katsuki’s overheated skin, followed by the deliberate slide of Izuku’s hand inside. He wrapped his fingers around Katsuki’s cock, already thick and heavy, the foreskin drawn back from the flushed, leaking head.

“Fuck,” Katsuki gasped, his head dropping.

“Look at you,” Izuku murmured, his eyes locked on their reflection. He began to stroke, a slow, tight glide from root to tip. His thumb swiped over the slit, spreading the wetness. “Look at us. This is what you want. More than her. More than any of it.”

Katsuki’s hips jerked. He tried to stifle it, but his body betrayed him, pushing into that clever, knowing grip. His cock was fully hard now, a thick, veined weight in Izuku’s hand. Precum beaded and dripped, smearing Izuku’s knuckles.

“You’re dripping for me,” Izuku said, his voice thick with pleasure. “On your wedding day. What does that make you, Kacchan?”

“Don’t,” Katsuki choked out, but his eyes were open, staring at the image in the glass: his own disheveled hair, his parted lips, Izuku’s cheek pressed to his, the younger man’s focused, serene expression as he worked Katsuki’s cock with practiced ease.

“Tell me to stop.” Izuku’s pace quickened, his wrist twisting on the upstroke. His other hand slipped around Katsuki’s waist, holding him still. “Say it. Say ‘stop, Izuku.’ Say ‘I’m marrying your mother.’”

Katsuki’s jaw worked. A groan tore from his throat, raw and helpless. His hips pistoned, fucking into Izuku’s fist. The mirror rattled against the wall.

“That’s it,” Izuku encouraged, breathless. He watched Katsuki’s face unravel in the mirror. “Come on. Let it go. I’ll clean you up. No one will know.”

The orgasm built like a fault line slipping, deep and inevitable. Katsuki’s vision blurred at the edges. He was panting, sweat beading at his temples. “Izuku—”

“Come for me, Daddy.” Izuku’s voice was a hot, wicked promise. “Come all over my hand. Then I’ll put you back together, and you’ll go say your vows.”

Katsuki cummed with a shattered cry, his body bowing. Thick stripes of white shot spattering the mirror. Izuku milked him through it, his grip firm, until Katsuki shuddered and went limp, spent and hollow.

For a long moment, the only sound was Katsuki's ragged breathing. Izuku slowly withdrew his hand, bringing his slick, coated fingers to his mouth. He never broke eye contact in the reflection as he licked them clean, his tongue sliding between his knuckles. “You taste like guilt,” he said softly. “And mine.”

He reached for a hand towel, wiping Katsuki clean with startling tenderness before tucking him away and zipping his trousers. He smoothed the wrinkled fabric, fastened the button. He adjusted Katsuki’s tie, his fingers deft. “There,” he whispered, stepping back. “Presentable.”

Katsuki stared at his own wrecked face. The man in the glass was a stranger—flushed, hollow-eyed, a groom ruined an hour before his wedding. Izuku looked pristine, victorious, a faint, satisfied smile on his lips.

The stairwell door clicked shut, sealing them in concrete echo and the faint smell of industrial cleaner. Denki didn’t let go of Eijiro’s wrist. He backed him up against the cold wall, his bright yellow eyes gleaming in the fluorescent light. “So. Best Man.”

Eijiro’s face was already flushed. “You… I’ve seen your work.”

“My work?” Denki grinned, leaning in. His free hand came up, a finger tracing the hard line of Eijiro’s bicep through his dress shirt. “You mean my videos. Which ones?”

“I— That’s not—” Eijiro stammered, his usual confident baritone gone shaky. He was a mountain of a man, but he’d gone completely still under Denki’s touch.

“The one with the pool floatie?” Denki’s voice dropped to a conspiratorial whisper. His knee nudged between Eijiro’s thighs, not hard, just present. “Or the one in the library? You seem like a library guy. All that quiet… until it isn’t.”

“All of them,” Eijiro blurted out, the words echoing in the stairwell. His face was crimson. “Every single one. The pool, the library, the one in the garage with the… the wax.”

Denki’s grin widened. He didn’t move his knee from between Eijiro’s thighs. “You kept a list. That’s adorable.” His finger left Eijiro’s bicep, tracing up to his shoulder, then along the thick line of his neck. “So you know what I can do.”

“It’s not— I wasn’t—” Eijiro swallowed, his adam’s apple bobbing under Denki’s touch. “They’re just… well-produced.”

“They are,” Denki agreed cheerfully. He leaned in, his lips almost brushing Eijiro’s jaw. His voice dropped to a murmur. “But you didn’t watch them for the production value, Eijiro. You watched them for the way I take a cock. The way I scream.”

Eijiro made a choked sound. His hands, which had been hanging at his sides, twitched. He didn’t push Denki away. His body was a tense wall of muscle, held captive by a feather-light touch.

“Izuku said you’d be fun,” Denki whispered. He finally moved his knee, a deliberate, slow press higher. “He said you were the guard dog. But guard dogs get treats, right?”

“My job is to be with Katsuki,” Eijiro managed, his voice rough. “Until he walks down the aisle.”

“And you will be.” Denki’s other hand came up, cradling Eijiro’s face. His thumb stroked over the man’s lower lip. “But right now, your best friend is getting the help he really needs. And you’re off-duty. For me.”

Eijiro’s resolve visibly fissured. His red eyes were locked on Denki’s, wide with a conflict that was already lost. He’d seen this mouth do unspeakable things on screen. Now it was inches from his, smiling just for him.

“Tell me,” Denki prompted, his breath warm against Eijiro’s skin. “What was your favorite part? Of any of them.”

The silence stretched. A door slammed somewhere floors below. Finally, Eijiro’s shoulders slumped. The confession came out defeated, hushed. “The… the squirt. In the library one. You came so hard you soaked the books.”

Denki laughed, a bright, delighted sound. “You’re a romantic.” He closed the last inch, pressing his mouth to Eijiro’s in a soft, closed-lipped kiss. It was chaste, but it burned. When he pulled back, Eijiro was staring, dazed. “I can do that live, you know. If you’re good.”

“Denki…”

“Shhh.” Denki sealed their mouths together again, and this time, he parted his lips. He licked his way inside, and Eijiro groaned, a deep, surrendered sound. The big man’s hands finally moved, coming up to grip Denki’s hips, holding him there as if he might float away.

Denki melted into him, all pliant confidence. He ground his pelvis against Eijiro’s thigh, a slow, filthy roll. He could feel the hard line of Eijiro’s arousal against his stomach. When he broke the kiss, a string of saliva connected them for a second in the harsh light. “See?” Denki whispered, his own breath coming faster. “Better than standing in a hallway looking stern.”

“I have responsibilities,” Eijiro breathed, but his hands were sliding up Denki’s back, pulling him closer.

“And I’m your responsibility now.” Denki nipped at his lower lip. “Izuku’s orders. Keep the best man… occupied. Happy. However I want.”

Denki’s grin turned wicked. “I want to suck your cock,” he breathed against Eijiro’s mouth, his fingers dropping to the man’s belt. “Right here. Let me see the famous Kirishima discipline.”

Eijiro’s protest died as Denki sank to his knees on the cold concrete. He fumbled with the belt, then the button, the zipper. He tugged Eijiro’s trousers and briefs down just enough. What sprung free made Denki’s bright yellow eyes go huge. “Oh, fuck,” he whispered, his voice full of genuine awe.

It was a monster. Thick as his wrist and long, a heavy, uncut 11 inches of flushed, veined flesh that curved upward. It jutted out from a thatch of black hair, the head already glistening. Denki’s mouth actually watered. He licked his lips. “You’re a goddamn horse,” he said, laughter and hunger mixing in his tone.

“Denki…” Eijiro’s voice was a strangled groan. His hands hovered near Denki’s head, wanting to push or pull, he didn’t know.

“Shhh.” Denki’s gaze fixed. He leaned forward, nuzzling the hot, musky skin of Eijiro’s lower belly before he pressed an open-mouthed kiss to the base. He inhaled deeply. “I’ve seen a lot of cocks. This is… a monument.” He licked a slow, flat stripe up the prominent underside vein, from root to tip, collecting the bitter-salt bead of pre-cum there. He hummed, the vibration making Eijiro jerk. “Tastes like a secret.”

He took the head into his mouth, his lips stretching wide. He could only manage the first few inches, his jaw already aching. He swirled his tongue around the crown, under the foreskin, suckling gently. Eijiro’s hips twitched forward. A low, guttural sound echoed in the stairwell.

“You’ve thought about this,” Denki said, pulling off with a wet pop. He stroked the shaft with both hands, his fingers not meeting. “Watching me on your screen, wishing it was you. Wishing you could fill me up like that.”

“Yes,” Eijiro choked out, the admission ripped from him. His hands finally settled in Denki’s fluffy hair, not forcing, just holding. “God, yes.”

Denki took him back into his mouth, deeper this time, working his jaw open wider. He focused on the head, sucking hard, using his hands to pump the massive length he couldn’t take. The sounds were obscene: wet, rhythmic pulls, Eijiro’s ragged breathing, the faint rustle of fabric. Denki looked up, his yellow eyes meeting Eijiro’s dazed red ones. Tears of strain welled in the corners of Denki’s eyes from the stretch, but he held the gaze, making a show of it.

Eijiro was unraveling. His professional concern for Katsuki, his duty, it all blurred under the relentless heat of Denki’s mouth. “I’m supposed to be… with him…” he managed, his voice thick.

Denki pulled off, a string of saliva connecting his lips to the slick head. “He’s busy,” he said, his voice husky. He leaned his cheek against the hot, throbbing shaft, nuzzling it. “Getting the wedding night treatment a little early. You’re just getting a preview. Now be a good best man and let me make you forget your own name.”

Denki took a breath, his yellow eyes glinting with challenge, and then he swallowed Eijiro down, down, taking the massive, veined length deep into his throat until his nose pressed into the coarse black hair at the base. He held it, his throat working around the intrusion, tears spilling freely down his cheeks. The sight—the complete, obscene submission—snapped the last thread of Eijiro’s control.

“Fuck,” Eijiro snarled, his voice raw. He hauled his cock out with a wet pop that echoed in the stairwell, his hands gripping Denki’s fluffy hair. He spun him around, holding his head against the cold concrete wall. “Open.”

Denki gasped, his mouth fell open obediently, hungry. Eijiro didn’t tease. He guided himself back between those lips and shoved forward, burying every inch down Denki’s throat in one brutal, desperate thrust.

Denki gagged, a wet, choked sound, but his hands flew back to grip Eijiro’s muscular thighs, holding on. Eijiro fucked his mouth with a ragged, punishing rhythm, each drive punching a muffled grunt from Denki’s chest. The sounds were animal: skin slapping, ragged breaths, the slick, rhythmic choke of a throat being used.

“You’re my fucking fantasy,” Eijiro groaned, his hips pistoning. One big hand cradled Denki’s head, holding him steady against the wall. “A dirty, perfect fantasy.”

Denki couldn’t speak, could only take it, his eyes rolled back in blissful strain. Spit dripped down his chin, onto the front of his shirt. He moaned around the thick flesh, the vibration making Eijiro curse and thrust harder.

“Katsuki—” Eijiro grunted, the name a pained confession between thrusts. “I’m supposed to be—ah, god—right there with him.”

He pulled almost all the way out, letting Denki drag in a shuddering, wet breath. “And where are you?” Eijiro demanded, his voice thick with lust and guilt.

Denki panted, his voice wrecked. “Right where you want me, Ei.” He tilted his head back, looking up, his yellow eyes hazy but smug. “Serving my best man.”

Eijiro drove back in, cutting off whatever else Denki might say. He was losing himself, the duty, the wedding, the friend he was betraying—all of it blurred into the heat of this throat, this willing, beautiful boy who knew exactly how to ruin him. “Gonna come,” he warned, his rhythm growing erratic, brutal.

Denki’s answer was to suck hard, applying vicious pressure on the upstroke, his tongue working frantically. That was all it took. Eijiro roared, a sound of pure surrender, and emptied himself down Denki’s throat in hot, pulsing streaks.

He stayed buried, shuddering, as Denki swallowed diligently, milking him with gentle, coaxing sucks until he was soft. Finally, Eijiro slumped back, pulling out. Denki catching his breath. He wiped his mouth with the back of his hand, a triumphant, tired smile on his face.

Eijiro leaned heavily against the opposite wall, tucking himself away with trembling hands. His red eyes were wide, shell-shocked. “I… I have to get to the church.”

Denki laughed, a bright, airy sound that bounced off the concrete walls. He pushed off from the wall and closed the distance between them, leaning up to press a soft, quick kiss to Eijiro’s stunned mouth. “There,” he said, his voice raspy from use. “Now you’re properly welcomed.”

“I have to get to the church,” Eijiro repeated, the words hollow. He was buttoning his trousers with clumsy fingers, refusing to meet Denki’s eyes.

“You will.” Denki traced a finger down the center of Eijiro’s broad chest. “But find me during the reception. I’m a plus-one. I’ll be the one staring.” His yellow eyes gleamed. “I need that fat cock to fuck my pussy. Properly. Not just down my throat.”

Eijiro’s head snapped up, his red eyes wide. “You can’t be serious.”

“Deadly.” Denki’s grin was all sunshine and filth. He adjusted his own clothes, wiping the last smear from his chin. “Izuku’s orders are to keep you occupied. I’m just… exceeding expectations. See you at the altar, best man.”

He slipped out the stairwell door, leaving Eijiro alone with the smell of sex and concrete dust. Eijiro slumped against the wall, dragging a hand down his face. His heart was a frantic drum against his ribs. Katsuki. The ceremony. His duty. All of it was a distant scream under the roaring memory of Denki’s throat, hot and yielding.